<?php
/**
 * Zend Framework
 * LICENSE
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 * @category Zend
 * @package Zend_Db
 * @subpackage Statement
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 * @version $Id: Sqlsrv.php 24593 2012-01-05 20:35:02Z matthew $
 */
/**
 *
 * @see Zend_Db_Statement
 */
require_once 'Zend/Db/Statement.php';

/**
 * Extends for Microsoft SQL Server Driver for PHP
 * @category Zend
 * @package Zend_Db
 * @subpackage Statement
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 */
class Zend_Db_Statement_Sqlsrv extends Zend_Db_Statement {

    /**
     * The connection_stmt object original string.
     */
    protected $_originalSQL;

    /**
     * Column names.
     */
    protected $_keys;

    /**
     * Query executed
     */
    protected $_executed = false;

    /**
     * Prepares statement handle
     * @param string $sql
     * @return void
     * @throws Zend_Db_Statement_Sqlsrv_Exception
     */
    protected function _prepare ($sql) {
        $connection = $this -> _adapter -> getConnection ();
        $this -> _stmt = sqlsrv_prepare ($connection, $sql);
        if ( ! $this -> _stmt) {
            require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
            throw new Zend_Db_Statement_Sqlsrv_Exception (sqlsrv_errors ());
        }
        $this -> _originalSQL = $sql;
    }

    /**
     * Binds a parameter to the specified variable name.
     * @param mixed $parameter Name the parameter, either integer or string.
     * @param mixed $variable Reference to PHP variable containing the value.
     * @param mixed $type OPTIONAL Datatype of SQL parameter.
     * @param mixed $length OPTIONAL Length of SQL parameter.
     * @param mixed $options OPTIONAL Other options.
     * @return bool
     * @throws Zend_Db_Statement_Exception
     */
    protected function _bindParam ($parameter, &$variable, $type = null, $length = null, $options = null) {
        // Sql server doesn't support bind by name
        return true;
    }

    /**
     * Closes the cursor, allowing the statement to be executed again.
     * @return bool
     */
    public function closeCursor () {
        if ( ! $this -> _stmt) {
            return false;
        }
        sqlsrv_free_stmt ($this -> _stmt);
        $this -> _stmt = false;
        return true;
    }

    /**
     * Returns the number of columns in the result set.
     * Returns null if the statement has no result set metadata.
     * @return int The number of columns.
     */
    public function columnCount () {
        if ($this -> _stmt && $this -> _executed) {
            return sqlsrv_num_fields ($this -> _stmt);
        }
        return 0;
    }

    /**
     * Retrieves the error code, if any, associated with the last operation on
     * the statement handle.
     * @return string error code.
     */
    public function errorCode () {
        if ( ! $this -> _stmt) {
            return false;
        }
        $error = sqlsrv_errors ();
        if ( ! $error) {
            return false;
        }
        return $error[0]['code'];
    }

    /**
     * Retrieves an array of error information, if any, associated with the
     * last operation on the statement handle.
     * @return array
     */
    public function errorInfo () {
        if ( ! $this -> _stmt) {
            return false;
        }
        $error = sqlsrv_errors ();
        if ( ! $error) {
            return false;
        }
        return array($error[0]['code'], $error[0]['message']);
    }

    /**
     * Executes a prepared statement.
     * @param array $params OPTIONAL Values to bind to parameter placeholders.
     * @return bool
     * @throws Zend_Db_Statement_Exception
     */
    public function _execute (array $params = null) {
        $connection = $this -> _adapter -> getConnection ();
        if ( ! $this -> _stmt) {
            return false;
        }
        if ($params !== null) {
            if ( ! is_array ($params)) {
                $params = array($params);
            }
            $error = false;
            // make all params passed by reference
            $params_ = array();
            $temp = array();
            $i = 1;
            foreach ($params as $param) {
                $temp[$i] = $param;
                $params_[] = &$temp[$i];
                $i ++ ;
            }
            $params = $params_;
        }
        $this -> _stmt = sqlsrv_query ($connection, $this -> _originalSQL, $params);
        if ( ! $this -> _stmt) {
            require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
            throw new Zend_Db_Statement_Sqlsrv_Exception (sqlsrv_errors ());
        }
        $this -> _executed = true;
        return ( ! $this -> _stmt);
    }

    /**
     * Fetches a row from the result set.
     * @param int $style OPTIONAL Fetch mode for this fetch operation.
     * @param int $cursor OPTIONAL Absolute, relative, or other.
     * @param int $offset OPTIONAL Number for absolute or relative cursors.
     * @return mixed Array, object, or scalar depending on fetch mode.
     * @throws Zend_Db_Statement_Exception
     */
    public function fetch ($style = null, $cursor = null, $offset = null) {
        if ( ! $this -> _stmt) {
            return false;
        }
        if (null === $style) {
            $style = $this -> _fetchMode;
        }
        $values = sqlsrv_fetch_array ($this -> _stmt, SQLSRV_FETCH_ASSOC);
        if ( ! $values && (null !== $error = sqlsrv_errors ())) {
            require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
            throw new Zend_Db_Statement_Sqlsrv_Exception ($error);
        }
        if (null === $values) {
            return null;
        }
        if ( ! $this -> _keys) {
            foreach ($values as $key => $value) {
                $this -> _keys[] = $this -> _adapter -> foldCase ($key);
            }
        }
        $values = array_values ($values);
        $row = false;
        switch ($style) {
            case Zend_Db::FETCH_NUM :
                $row = $values;
                break;
            case Zend_Db::FETCH_ASSOC :
                $row = array_combine ($this -> _keys, $values);
                break;
            case Zend_Db::FETCH_BOTH :
                $assoc = array_combine ($this -> _keys, $values);
                $row = array_merge ($values, $assoc);
                break;
            case Zend_Db::FETCH_OBJ :
                $row = (object) array_combine ($this -> _keys, $values);
                break;
            case Zend_Db::FETCH_BOUND :
                $assoc = array_combine ($this -> _keys, $values);
                $row = array_merge ($values, $assoc);
                $row = $this -> _fetchBound ($row);
                break;
            default :
                require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
                throw new Zend_Db_Statement_Sqlsrv_Exception ("Invalid fetch mode '$style' specified");
                break;
        }
        return $row;
    }

    /**
     * Returns a single column from the next row of a result set.
     * @param int $col OPTIONAL Position of the column to fetch.
     * @return string
     * @throws Zend_Db_Statement_Exception
     */
    public function fetchColumn ($col = 0) {
        if ( ! $this -> _stmt) {
            return false;
        }
        if ( ! sqlsrv_fetch ($this -> _stmt)) {
            if (null !== $error = sqlsrv_errors ()) {
                require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
                throw new Zend_Db_Statement_Sqlsrv_Exception ($error);
            }
            // If no error, there is simply no record
            return false;
        }
        $data = sqlsrv_get_field ($this -> _stmt, $col); // 0-based
        if ($data === false) {
            require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
            throw new Zend_Db_Statement_Sqlsrv_Exception (sqlsrv_errors ());
        }
        return $data;
    }

    /**
     * Fetches the next row and returns it as an object.
     * @param string $class OPTIONAL Name of the class to create.
     * @param array $config OPTIONAL Constructor arguments for the class.
     * @return mixed One object instance of the specified class.
     * @throws Zend_Db_Statement_Exception
     */
    public function fetchObject ($class = 'stdClass', array $config = array()) {
        if ( ! $this -> _stmt) {
            return false;
        }
        $obj = sqlsrv_fetch_object ($this -> _stmt);
        if ($error = sqlsrv_errors ()) {
            require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
            throw new Zend_Db_Statement_Sqlsrv_Exception ($error);
        }
        /* @todo XXX handle parameters */
        if (null === $obj) {
            return false;
        }
        return $obj;
    }

    /**
     * Returns metadata for a column in a result set.
     * @param int $column
     * @return mixed
     * @throws Zend_Db_Statement_Sqlsrv_Exception
     */
    public function getColumnMeta ($column) {
        $fields = sqlsrv_field_metadata ($this -> _stmt);
        if ( ! $fields) {
            throw new Zend_Db_Statement_Sqlsrv_Exception ('Column metadata can not be fetched');
        }
        if ( ! isset ($fields[$column])) {
            throw new Zend_Db_Statement_Sqlsrv_Exception ('Column index does not exist in statement');
        }
        return $fields[$column];
    }

    /**
     * Retrieves the next rowset (result set) for a SQL statement that has
     * multiple result sets.
     * An example is a stored procedure that returns
     * the results of multiple queries.
     * @return bool
     * @throws Zend_Db_Statement_Exception
     */
    public function nextRowset () {
        if (sqlsrv_next_result ($this -> _stmt) === false) {
            require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
            throw new Zend_Db_Statement_Sqlsrv_Exception (sqlsrv_errors ());
        }
        // reset column keys
        $this -> _keys = null;
        return true;
    }

    /**
     * Returns the number of rows affected by the execution of the
     * last INSERT, DELETE, or UPDATE statement executed by this
     * statement object.
     * @return int The number of rows affected.
     * @throws Zend_Db_Statement_Exception
     */
    public function rowCount () {
        if ( ! $this -> _stmt) {
            return false;
        }
        if ( ! $this -> _executed) {
            return 0;
        }
        $num_rows = sqlsrv_rows_affected ($this -> _stmt);
        // Strict check is necessary; 0 is a valid return value
        if ($num_rows === false) {
            require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
            throw new Zend_Db_Statement_Sqlsrv_Exception (sqlsrv_errors ());
        }
        return $num_rows;
    }

    /**
     * Returns an array containing all of the result set rows.
     * @param int $style OPTIONAL Fetch mode.
     * @param int $col OPTIONAL Column number, if fetch mode is by column.
     * @return array Collection of rows, each in a format by the fetch mode.
     *         Behaves like parent, but if limit()
     *         is used, the final result removes the extra column
     *         'zend_db_rownum'
     */
    public function fetchAll ($style = null, $col = null) {
        $data = parent::fetchAll ($style, $col);
        $results = array();
        $remove = $this -> _adapter -> foldCase ('ZEND_DB_ROWNUM');
        foreach ($data as $row) {
            if (is_array ($row) && array_key_exists ($remove, $row)) {
                unset ($row[$remove]);
            }
            $results[] = $row;
        }
        return $results;
    }

}
